Blast lance car arrangement for metallurgical furnace



United States Patent [72] lnventor Werner Marxen Duisburg, Germany [21] Appl. No. 644,980 [22] Filed June 9, 1967 [45] Patented Dec. 22, 1970 [73] Assignee Demag Aktiengesellschaft Duisburg, Germany [32] Priority July 14, 1966 [33] Germany [31] No. B50564 [54] BLAST LANCE CAR ARRANGEMENT FOR METALLURGICAL FURNACE 9 Claims, 4 Drawing Figs.

[52] 11.8. CI 266/34 [51] Int. Cl C2lc 7/00 [50] Field of Search 266/341, 34.2, 35, 42, 34, 34T, 43; 214/32 [56] References Cited UNITED STATES PATENTS 966,986 8/ 1910 Barnett et a1. 214/32 2,314,686 3/1943 Brosius 214/32X 3,063,699 11/1962 Read 266/34 3,150,963 9/1964 Kurzinski 266/34X 3,201,107 8/1965 Kramer 266/36 Primary Examiner-J. Spencer Overholser Attorney-Me Glew and Toren ABSTRACT: A metallurgical furnace particularly of the hearth-type includes a reduced dimension portion forming a mouth having an opening through which a lance may be inserted. 1n the preferred arrangement, the mouth opening may advantageously be closed by an exhaust gas hood which is adapted to move along a trackway at right angles to the opening to permit opening and closing of the mouth. A lance carrier or car is arranged to move along a trackway directly opposite the opening of the furnace in directions parallel to the axis of the opening. A lance guide or carrying trolley is movable along a pivotal trolley at the outer end of the lance car which is arranged toward the furnace mouth opening. The trolley trackway is carried on a segment member which may be pivoted about a horizontal axis in order to permit accurate orientation of the angle of the lance for penetration through the mouth of the furnace and down into the melt therein. The lance guide which carries the lance may be moved backwardly and forwardly in axial directions in respect to the lance along the top portion of the segment which defines a trackway for the guide. Pivotal movement of the segment carrying the lance guide trackway is effected by a motor drive and the movement of the lance car backwardly and forwardly along its associated trackway is effected by a separate electrical drive, the lance car being guided on its trackway by upwardly and downwardly bearing wheel sets.

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' sum 2 0F'2 Inventor WERNER "MIKE N WMMWZW BLAST LANCE CAR ARRANGEMENT FOR METALLURGICAL FURNACE SUMMARY OF THE INVENTION This invention relates in general to the construction of metallurgical furnaces and accessories therefor and in particular to a new and useful arrangement for. a lance car and trackway at a spaced location from the furnace with the lance car being guided. for movement toward and away from the mouth opening of the furnace and to the construction of a lance car for supporting a lance guide on the car in a manner such that the lance may be advanced and retracted axially and pivoted about a horizontal axis as desired.

The invention relates in particular to a hearth-type furnace, rotary furnace, converter and the like wherein the furnace is provided with a mouth of reduced dimension having an opening through which a lance must be introduced during the operating procedure. The known devices for introducing lances include carriers which either are stationary or mounted on cars. In either case the lance displacement device is such that it will block the space in front of the furnace mouth so that additional devices may not be employed. Thus, it is not possible to move additional devices to the furnace during the lance operating periods. More important, however, is the fact that the furnaces which may be either movable or which will require a certain distance from the surrounding hall frame parts do not permit the extension of a platform or track to the edge of the furnace mouth. For this reason, there is no optimum arrangement at the present time for the interrelated functional elements of the furnace vessels including the lance car and the exhaust gas hood which is adapted to close the mouth of the furnace. Suggestions for the combining of the lance car with the exhaust gas hood cannot be realized because the track cannot be extended up to the furnace mouth. In addition, the combining of these two functions does not permit the lance to be introduced into the furnace mouth to achieve best metallurgical effect.

It is also necessary to consider the fact that the furnace mouth must be kept as small as possible because of heat losses. In some instances the narrow opening atthe mouth is further reduced by water-cooled packing. Although such packing is omitted in revolving furnaces, the heat loss is quite large.

In accordance with the present invention there is provided an arrangement for a mouth cover or gas hood and a lance car such that the hood may be moved into and out of engagement with the mouth opening independently of the positioning or 1 maneuvering of the operation of the lance and its associated lance car. For this purpose, the gas hood is mounted for movement along tracks which extend substantially perpendicular to the axis of the opening. A lance car is adapted to move along tracks which extend toward and away from the opening but the tracks do not extend up to the point at which they interfere with the maneuvering of the gas hood. For this reason, the lance car includes an overhanging portion which may be projected outwardly from the end of its trackway to breech the gap to the furnace. The lance car provides a mounting for a segment member which forms a platform for a trolley or lance guide which holds the .outer end of the lance and may be shifted back and forth along the trackway to shift the position of the lance axially. The segment is pivotally mounted and may be moved by a motor drive to tilt the lance guide and the lance associated therewith about a substantially horizontal axis so that it may be oriented at a desired angle in respect to the furnace opening and in respect to the melt in the furnace. The trackway for the lance car is advantageously mounted at an elevation above the trackway for the gas hood and when the gas hood is removed from the opening, the outer end of the lance car may be projected over the trackway for the gas hood to orient the pivotal segment with the trolley for the lance guide directly adjacent the opening of the mouth of the furnace. With such an arrangement it is possible to meet the requirements for favorable approach to the furnace mouth of the lance. The lance car is made to a length such that the space between the termination of its track and the furnace mouth can be bridged over and the lance can be moved into and out of the mouth of the furnace by shifting the lance guide. With such a construction, the level of the melt and the form of the mouth and the opening thereof do not provide any particular difficulties in respect to the orientation of the lance.

The favorable approach to the furnace by the lance may be further enhanced in accordance with the invention by maintaining the self-supporting span of the lance car so short in the operating position of the lance that the lance s outer end may be oriented in the melt at a desired angle without the lance or its associated guide coming into contact with any portion of the inner or outer ends of the fumace mouth passage. With the construction of the invention the lances may be made shorter and therefore less expensive than required with the present handling equipment.

The arrangement of the lance car and its trackway are such that the lance may be introduced into the furnace in two phases. In the first phase the introduction is effected in a horizontal axial direction in respect to the lance up to a determinable end point on the track for the lance car. Thereafter, the lance is then pivoted about a horizontal axis until it is oriented at a favorable angle in respect to the melt. This angle is determined substantially by the energy of the blasting agent at the nozzle opening, by the exit energy of the blasting agent from the nozzle, by the size of the charge and by the size of the hearth. Consequently, considerable additional metallurgical advantages are achieved with the short clamped lance.

In hearth-type furnaces such as so-called tandem furnaces, there is an additional special effect inasmuch as a steep dipping direction or orientation of the lance can be obtained and because of the shorter lance length and the size of the associated handling equipment there is a lesser degree of obstruction of the furnace vault. The shorter length of the lance has the further advantage that the residues from the slag and melting bath do not produce heavy deposits on the lance which would cause an undue stressing and bending thereof.

By mounting the lance guide on a trackway formed on the upper portion of a toothed or geared segment, an extremely accurate positioning of the lance may be obtained by pivoting the segment by a driving gear arrangement. The position of the lance may be adjusted or corrected by small amounts as desired. The segment is supported at the outer end of the lance car on a cantilever portion thereof, but nevertheless a compact swiveling device is provided which is insensitive to vibrations. I v

In accordance with a further feature of the invention the guide or trackway for the lance car includes track elements which face upwardly and downwardly on each side of the car and which are engaged by oppositely engaging wheel elements so that a rigid well founded and vibration-free support is provided for the lance car in all positions and conditions of operation.

Accordingly it is an object of the invention to provide an improved metallurgical furnace arrangement for positioning a lance in respect to the furnace.

A further object of the invention is to provide a lance car support for a metallurgical furnace which includes a trackway for a lance car which terminates at a spaced opening from the mouth of the furnace and wherein the lance car is provided with an overhanging portion which may be moved outwardly beyond the trackway to the furnace, and which carries at its outer end a pivotal support for a lance to permit the lance to be oriented in respect to the furnace.

A further object of the invention is to provide an arrangement for a metallurgical furnace which includes a trackway for guiding a gas hood or cover extending in the plane of the opening and a trackway at an elevated location for a lance car which extends at right angles to the trackway for the cover but which terminates before the cover trackway and wherein the lance car is provided with an overhanging portion for pivotally mounting a lance such that it may be oriented in respect to the furnace.

.A further object of the invention is to provide a lance car construction and a metallurgical furnace arrangement which are simple in design, provide a durable arrangement and rugged construction and are economical to manufacture and operate.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of this invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there is illustrated and described a preferred embodiment of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a partial transverse sectional view and elevational view of a metallurgical furnace and a lance car arrangement therefor constructed in accordance with the invention;

FIG. 2. is a view similar to FIG. 1 with the lance car indicated in a retracted position and with the gas hood in position closing the mouth opening of the furnace;

FIG. 3 is a partial top plan view of the lance car indicated in FIG. 1; and

FIG. 4 is a section taken along the line IVIV of FIG. 3.

DETAILED DESCRIPTION Referring to the drawings in particular, the invention embodied therein comprises a lance and cover or gas hood system for a hearth-type furnace designated 1 having a melting bath 2 into which a lance 3 is dipped.

- In accordance with the invention, the lance 3 is rigidly engaged at its outer end by a lance guide or trolley 4 having wheels 4a which are movable on channel members defining a trackway 5. The trackway 5 is mounted on the upper portion of a segment member 6. The lance guide 4 may be moved backwardly and forwardly along the trackway 5 by means of a fluid cylinder operator comprising a cylinder 21 mounted directly below the trackway 5 which carries a rod 21a which engages the guide 4 and moves the guide between the dotted and the solid line positions indicated in FIG. 1.

The segment 6 is carried at the outer end of a cantilever or overhang end portion 8a of a lance car 8 and it is pivotally mounted about a pivot member 7 which is joumaled between spaced end portions of the cantilever portion in a position below the trackway 5 by which it is protected. The segment 6 may be pivoted about the bearing 7 by actuation of a motor 12 driving through reducing gearing 11 and a gear which meshes with a gear portion 9 defined on the outer periphery of the segment 6. The drive and the construction is such that the tilting position of the segment 6 and the angular disposition of the trackway and the lance 3 may be accurately controlled arid precisely moved.

In accordance ,with a feature of the invention, the car 8 is provided with upper and lower sets of wheels 14, 14 and 15, 15, respectively (FIGS. 1 and 4), which engage track elements 13,13 which face upwardly and track elements 13', 13' which face downwardly, respectively. At least two sets of such wheels are provided, as indicated in FIG. 3, so that the lance car8 is guided in a very stable manner and will be held on its associated trackway 13 substantially without vibration. The trackway 13 is supported by means of side support elements (FIG. 4) at a position at which it overlies a trackway 17 defined on the ground level or elevated platform 18 adjacent the mouth opening 10 of the furnace I. The end of the trackway 13 for the lance car 8 indicated at 13a is spaced away from the opening 10 of the furnace 1 by an amount sufficient for the movement of a gas hood or cover 19 which is cartied-on a wheeled frame 18 which moves along the trackway 17-. As indicated in FIG. 2, the hood 19 may be oriented to close the opening 1c after the lance 3 has been moved backwardly on the lance car 8, so that it does not project beyond the end 130 of the trackway 13 for the lance car.

The lance car 8 is driven by a motor 30 driving through a speed gear 16 to each wheel 14, 14 of at least one of the upper and lower wheel sets. When the cover 19 is removed from the front of the furnace, the motor 30 may be actuated to advance the car 8 toward the furnace opening 10 with the lance oriented in the horizontal position indicated 30 in FIG. 1. The movement may continue until, for example, the forward end or cantilever portion 8a of the lance car assumes the dotted line position 30 directly adjacent the opening 10. The motor 12 may then be actuated to cause a tilting movement of the segment 6 and the inclination of the lance 3 tothe position indicated 3b at which it is located below the level 32 of the melt 2. At this initial position point there will still be clearance between the lance and the edge of the furnace 1 at the location of the opening 1c. It should also be noticed that the lance car 8 may be retracted to the solid line position indicated in FIG. 1 without changing the lance angle, if desired, and even in this position there will still be a clearance between the lance 3 and the inner end In of the mouth passage 34.

While in the view indicated in FIG. 2 the exhaust gas hood 19 is located in a position adjacent the opening 1b and the lance 3 is shown in the removed position, it is also possible that both of these elements could be removed from the furnace opening 10 so that charging operations or other operations can be carried out.

Because the support 7 for the segment 6 is located at the extreme end 8a of the lance car 8, the desired high handling capacity at the edge of the furnace opening 10 and the inner edge 1a can be carried out. The lance car 8 will hold the lance 3 in an even vibration-free position at all times because of the framelike arrangement of the wheels which engage the tracks from the top and bottom sides. The wheels advantageously all include side edges so that they engage around the tracks 13 and 13 in a manner to limit sideways movement as well as up and down movement.

While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the inventive principles, it will be understood that the invention may be embodied otherwise without departing from such principles.

Iclaim:

I. An arrangement for a metallurgical furnace having a mouth with an opening for the introduction of a lance therethrough which lance may be dipped into the melt in the furnace, comprising a lance car trackway in front of the mouth of the furnace terminating at its inner end at a spaced location from the mouth of the furnace and extending in the general direction generally coaxially with the axis of the mouth of the furnace, a lance car movable along said lance car trackway and having an overhang portion which may be moved with said car and projects longitudinally over the space between the end of said lance car trackway to the mouth of said furnace, and lance holder means pivotally carried at the outer end of said overhang portion of said lance car for pivotally supporting a lance thereon for pivotal movement about a substantially horizontal axis, said car being movable on said trackway forward and away from said furnace mouth for shifting said lance inwardly and outwardly with respect to the furnace mouth.

2. An arrangement according to claim 1, wherein said lance holder means includes a member engageable around said, lance adjacent to its outer end, the overhang portion of said lance car being positionable so that lance holder means will, hold said lance so that it may be moved downwardly to dip the; outer end thereof into the melt of the furnace without the;

lance contacting the walls of the mouth adjacent the opening.

3. An arrangement according to claim 1, wherein said lance holder means comprises a segment pivotally mounted ad-. jacent the outer end of said overhang portion of said lance car, and gear means connected to said segment for pivoting said;

segment to tilt the lance about an axis which is substantially horizontal.

4. An arrangement for a metallurgical furnace having a mouth with an opening for the introduction of a lance therethrough which lance may be dipped into the melt in the furnace, comprising a lance car trackway in front of the mouth of the furnace terminating at its inner end at a spaced location from the mouth of the furnace and extending in the general direction away from the mouth of the furnace, a lance car movable along said lance car trackway and having an overhang portion which may be moved with said car to project over the space between the end of said lance car trackway to the mouth of said furnace, lance holder means pivotally carried adjacent the outer end of said overhang portion of said lance car for pivotally supportinga lance thereon for pivotal movement about a substantially horizontal axis, said lance holder means comprising a segment pivotally mounted adjacent the outer end of said overhang portion of said lance car, a trackway defined along the upper portion of said segment, a lance holder engageable with theouter end of a lance and adapted to be moved along said trackway in axial directions in respect to the lance, and means engaged with said segment for pivoting said segment to orient'the lance at a desired angle.

5. An arrangement for a metallurgical furnace having a mouth with an opening for the introduction of a lance therethrough which lance may be dipped into the melt in the furnace, comprising a lance car trackway in front of the mouth of the furnace terminating at its inner end at a spaced location from the mouth of the furnace and extending in the general direction away from the mouth of the furnace, a lance car movable along said lance car trackway and having an overhang portion which may be moved with said car to project over the space between the end of said lance car trackway to the mouth of said furnace, and lance holder means pivotally carried adjacent the outer end of said overhang portion of said lance car for pivotally supportinga lance thereon for pivotal movement about a substantially horizontal axis, said lance car trackway including spaced upper and lower track portions, said lance car having at least one wheel set with wheels engaging said upper and lower track portions in opposite directions.

6. An arrangement for a metallurgical furnace having a mouth with an opening for the introduction of a lance therethrough which lance may be dipped into the melt in the furnace, comprising a lance car trackway in front of the mouth of the furnace terminating at its inner end at a spaced location from the mouth of the furnace and extending in the general direction away from the mouth of the furnace, a lance car movable along said lance car trackway and having an overhang portion which may be moved with said car to project over the space between the end of said lance car trackway to the mouth of said furnace, lance holder means pivotally carried at the outer end of said overhang portion of said lance car for pivotally supporting a lance thereon for pivotal movement about a substantially horizontal axis, a gas hood trackway extending alongside the furnace adjacent the mouth disposed in a space between said lance car trackway and the mouth, and gas hood means movable along said gas hood trackway toward and away from the opening for orienting the gas hood means in operative association with the opening and for removing the gas hood means from operative association with the opening of said furnace.

7. An arrangement for a metallurgical furnace having a mouth with an opening for the introduction of a lance therethrough which lance may be dipped into the melt in the furnace, comprising a lance car trackway in front of the mouth of the furnace terminating at its inner end at a spaced location from the mouth of the furnace and extending in the general direction away from the mouth of the furnace, a lance car movable along said lance car trackway and having an overhang portion which may be moved with said car to project over the space between the end of said lance car trackway to the mouth of said furnace, lance holder means pivotally carried adjacent the outer end of said overhang portion of said lance car for pivotally supporting a lance thereon for pivotal movement about a substantially horizontal axis, said lance car including forward and rear upper and lower wheel sets engagin said trackway from above and from below said lance ho der means comprising a geared segment pivota ly mounted adjacent the outer end of said overhang portion, motor gear means connected to said geared segment for pivoting said segment, a trackway defined on the segment, and a lance holder adapted to be connected to the outer end of the lance and movable along said lance holder trackway in directions substantially axially in respect to the lance.

8. A lance car adapted to be moved along a trackway into and out of association with the opening in a mouth of a metallurgical furnace, comprising a body having a projecting cantilever portion adapted to project outwardly beyond the trackway with which the car is to be associated, and lance holder means carried adjacent the outer end of said overhanging cantilever portion for holding a lance for pivotal movement about a substantially horizontal axis, said lance holder means including a segment pivotally mounted adjacent the outer end of said overhang portion of said lance car, a lance guide trackway defined on said segment, a lance guide adapted to engage the outer end of said lance and being movable along said lance guide trackway for shifting said lance in axial directions, and means connected to said segment to pivot said segment for tilting the lance.

9. A lance car according to claim 8, including wheel means on said car adapted to engage a trackway from above and from below. 

